Smoke and gas burning firebox



C. E. BETCHER. SMOKE AND GAS BURNING FIREBOX.

APPLICATION FILED SEPT. 6, 1918.

3 SHEETS-SHEET I.

Patented Apr. 5, 1921.

C. E. BETCHER.-

SMOKE AND GAS BURNiNG FIREBOX- APPLICATION FILED SEPT. 6,1918.

Patented Apr. 5-, 192-1.

3.8HEETS-SHEET2'.

OO O III/III C. E. B'ETCHER. SMOKE AND GAS BURNING FIREBOX.

APPLICATION FltED SEPT. 61 l9l8.

Patented Apr. 5, 1921.

3SHEETSSHEET 3- In customary furnaces which are in use,

* "Ares a snoxln AND ens Bennnve rmnrox.

aramie.

Application filed September 6, 1918. Serial No. 252,834.

To all whom it may concern:

1 Be it known that I, CHESTER E-BET0HER, citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Smoke and Gas Burning F ireboxes, of which the following is a specification. I

.My invention relates to smoke and gas burning fire boxes for furnaces. An object of my invention is to provide means for securing more perfect combustion of fuel than is possible in furnaces which are now in common use, whether combustion is supported by air alone or by both air and steam.

only an imperfect combustion of the fuel is obtained because a large percentage ofthe gaseous products pass off unconsumed. The result of this is that a large amount of potential heat is wasted and quantities of smoke and soot are discharged into the) atmosphere with attendazitinjurious results. In carrying out my invention, I provide the fire-box with means which cause the smoke and gases coming from the fuel to be subjected to a high degree of heat before they are given an opportunity to escape through the chimney. I alsolprovide means'for preheating the air which is supplied to support the combustion of the gasesand smoke. By the provision of these means, I secure a steady and uniform heat and almost complete combustion of the combustible elements. This results in a great saving of fuel and elimination of smoke.

. Thefull objects andadvantages of my invention will appear in connection with the detailed description thereof, and the novel features embodied in my invention are particularly pointed out in the claims.

'Figure 1 is a longitudinal vertical section of a boiler furnace having my invention applied thereto. Fig.2 is a view in cross section looking toward the rear fire wall. Fig. 3 is a detailed View in longitudinal section showingthe lining of one of the Specification of Letters Patent.

Patented Apr. 5, 1921.

sides of the firebox partly broken away in order to show the flue'sin the side walls. Flg. 4 1s a view in cross section on the line 44 of F g. 1 looking inthe direction of the arrow. Fig. 5 is a View in horizontal sec tionon the line 55 of Fig. 1 looking in the direction of the arrow. I

In the drawings, 10 designates a boiler which may be of the usual construction set in brick workllconstituting the main walls of the furnace and having a stackior chimney 12. Underneath the rear portion ofthe boiler is a chamber l4'and underneath the front portion of the boiler is a fire-box 16.

The front of the firebox may be provided with one or more charging doors 18, but I prefer to provide a charging chute to be described later for supplying fuel to the fire-box. The bottom of the fire-box is constituted by grates 20 ofthe usual construction, two of these grates being prefer ably provided which are separated by a horizontal stationary bar 22. Underneath these grates is a main ashpit 24 and at the rear end of these grates is a transverse par tition 26 which extends from the grates about halfway to the bottom of the main ash-pit. At the rear of the grates 20 are secondary separate grates 28 under which is an auxiliary 'ash'pi't 3O separated from the mainashpit by the partition 26. The bot tom of the auxiliary ashpit consists of a pivoted plate 32 which normally lies in hori- Zontal position with its rear end upon a stop 84 and its front end abutting the lower end of the partition 26. The front of this 2 plate is provided with an arm to which is pivoted a rod 36 extending to the front of the furnace and by means of which the auxiliary ashpit may bedumped intothe main ashpit. The grates are operated by hand levers 38 to which they are connected in the usual manner. Located in the fire-box toward its rear end and spaced from its bottom so as to extend down to the fuel bed, are two transverse fire walls which constitute an essential feature of my invention. The rear fire wall 40 is curvedat its upper end so as to fit upon the boiler and make a tight joint therewith The front fire wall 42 is spaced from the rear fire wall so as to leave a passage-way 44 extending clear across'thefire-box. The wall 42 is shorter than the wall 40 whereby it is spaced from the boiler so as to leave a passageway connected with the passageway 44* The passageways 46 and 44 lead from the top of thefront portion of the fire-box and discharge at the bottom of the rear portion of the fire-box. Back of the firewalls is a space 45 extending between thewall 40j and a bridge wall 47, the latter being curved at its top and spaced a short distance from the boiler so as to provide a passage 49 leading into the chamber 14. The fire walls are formed from suitable refractory material which readily becomes highly heated and each of these walls is provided with a plurality of horizontal fines 48 with a plurality of openings .50 extending from each fiue through the rear portions of the walls whereby the fines in the wall 42 open directly into the passageway 44 and the fines in the wall 4O open into the space in the rear portion of the fire-box. Horizontal fines 52provided with dampers 53 extend from the-front of the furnace through the side walls of the fire-boxand these main fines connect by vertical fines 54 with the fines 48. Above the main fiues 52, the side walls of the fire-box are provided with a plurality of smaller fines 56 connected with the main fines by vertical fines 58. When the furnaces are of considerable size, the centers of the fire-walls 40 and 42 may be supported by blocks 60 resting upon the horizontal stationary bar 22. These blocks are provided with vertical air spaces 62, as best shown in Fig. 2. The charging chute previously referred to is shown in Fig. 4 This chute comprises a hopper portion 64, at the bottom of which is'a discharge portion 66 leading through the side wall of the furnace into the firebox directly in front of the firewall 42. At the lower end of the discharge portion is a hinged door 68 normally held in closed position by a chain 70 passing through a tube 72 to the outside of the furnace whereby the door may be held closed or open to any desired extent. The tube 72 may be provided with rollers such as shown at 74 to serve as guides for the chain. The hopper being filled with fuel, when it is desired to charge the furnace, the chain is released and the fuel is distributed into the fire-box in front of the fire-wall at different places according to the degree of opening of the door. When the door as shown in lower dotted lines is allowed to drop into, engagement with the beveled portion 76 of the side walls, the fuel is discharged into the fire-box adjacent this wall. When the door is lifted as shown in upper dotted lines so as to have a lesser inclination, the fuel will be discharged toward the opposite side wall of the fire-box.

The operation and advantages of my constructionwill be readily understood from the foregoing description. Practically all of the gases which are formed in the firebox are forced to pass through the passageway 44 between the highly heated walls 40 and 42 and these highly heated gases are mixed with preheatedair delivered through the openings 50 both betweenthe walls 40 and 42 and at the rear of the wall 40. The current of preheated air furnishes the oxygen necessary to support combustion and causes almost complete combustion of the gases which would otherwise escape up the chimney. This results in saving a large percentage of the fuel and prevents the discharge of smoke-from the chimney. The passage of air through the fines in the fire-. walls and through the fines in the side walls of the fire-box serves two purposes since it not only causes the air intended to support combustion to be preheated but keeps the wallsfrombecoming too highly heated and burning out, thus insuring the life of the fire walls and of the lining of the fire-box. The provision of the bottom plate 32 prevents cold air from "the front of the furnace passing up through the auxiliary ashpit into the rear. of the fire-box which condition, if allowed to exist, would lower the temperature of the burning gases. The charging chute delivers a fresh supply of fuel directly in front of the fire-wall 42 where the gases are effectively distilled and caused to pass through the space between the highly heatedfire walls where they are mixed with preheated air. The amount of cold air passing into the fire-box during charging is much less than it would be when fire walls in said fire-box, saidfire walls being spaced apart and the front fire wall beingshorter than the rear fire wall whereby a passage is provided over the front fire wall leading under the rear fire Well, said fire walls being provided with horizontal fines for supplying preheated air'to Support combustion and means for delivering fresh air to aid fines.

i 2. A furnace comprising a fire-box, two fire walls in said fire-box, said fire walls being spaced apart and the front fire wall being shorter than the rear fire wall whereby a passage is provided over the front fire wall leading under the rear fire-Wall, said front wall being provided with horizontal fines having openings into the space between the two walls and said rear walls being provided with horizontal fines having openings through the rear face thereof, and means for delivering freshair to both sets of fines.

3. A furnace comprising a fire-boxhaving horizontal fines in its side walls, two fire walls extending between said side walls, said fire walls being spaced apart and the. front firewall beingshorter than the rearfire Wall fire Wall leading under the rear fire Wall, the front fire Wall being shorter than the said fire Walls being provided With horizonrear fire Wall whereby a passage is provided tal flues having openings through the rear over the front fire Wall leading under the surfaces of the Walls, andmain flues for rear fire Wall, and blocks supporting the 5 supplying fresh air to the fines in the side center of each of said fire Walls, said blocks 15 Walls and to the flues in the fire Walls. resting upon said stationary bar.

4- A furnace comprising a fire-box hav- In testimony whereof I hereunto affix my ing a stationary bar extending across the signature.

bottom thereof, two fire Walls in said fire- V 10 box, said fire Walls being spaced apart and CHESTER E. BETCHER. 

